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jfs_logmgr.c
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jfs_logmgr.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) International Business Machines Corp., 2000-2004
* Portions Copyright (C) Christoph Hellwig, 2001-2002
*/
/*
* jfs_logmgr.c: log manager
*
* for related information, see transaction manager (jfs_txnmgr.c), and
* recovery manager (jfs_logredo.c).
*
* note: for detail, RTFS.
*
* log buffer manager:
* special purpose buffer manager supporting log i/o requirements.
* per log serial pageout of logpage
* queuing i/o requests and redrive i/o at iodone
* maintain current logpage buffer
* no caching since append only
* appropriate jfs buffer cache buffers as needed
*
* group commit:
* transactions which wrote COMMIT records in the same in-memory
* log page during the pageout of previous/current log page(s) are
* committed together by the pageout of the page.
*
* TBD lazy commit:
* transactions are committed asynchronously when the log page
* containing it COMMIT is paged out when it becomes full;
*
* serialization:
* . a per log lock serialize log write.
* . a per log lock serialize group commit.
* . a per log lock serialize log open/close;
*
* TBD log integrity:
* careful-write (ping-pong) of last logpage to recover from crash
* in overwrite.
* detection of split (out-of-order) write of physical sectors
* of last logpage via timestamp at end of each sector
* with its mirror data array at trailer).
*
* alternatives:
* lsn - 64-bit monotonically increasing integer vs
* 32-bit lspn and page eor.
*/
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/buffer_head.h> /* for sync_blockdev() */
#include <linux/bio.h>
#include <linux/freezer.h>
#include <linux/export.h>
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include "jfs_incore.h"
#include "jfs_filsys.h"
#include "jfs_metapage.h"
#include "jfs_superblock.h"
#include "jfs_txnmgr.h"
#include "jfs_debug.h"
/*
* lbuf's ready to be redriven. Protected by log_redrive_lock (jfsIO thread)
*/
static struct lbuf *log_redrive_list;
static DEFINE_SPINLOCK(log_redrive_lock);
/*
* log read/write serialization (per log)
*/
#define LOG_LOCK_INIT(log) mutex_init(&(log)->loglock)
#define LOG_LOCK(log) mutex_lock(&((log)->loglock))
#define LOG_UNLOCK(log) mutex_unlock(&((log)->loglock))
/*
* log group commit serialization (per log)
*/
#define LOGGC_LOCK_INIT(log) spin_lock_init(&(log)->gclock)
#define LOGGC_LOCK(log) spin_lock_irq(&(log)->gclock)
#define LOGGC_UNLOCK(log) spin_unlock_irq(&(log)->gclock)
#define LOGGC_WAKEUP(tblk) wake_up_all(&(tblk)->gcwait)
/*
* log sync serialization (per log)
*/
#define LOGSYNC_DELTA(logsize) min((logsize)/8, 128*LOGPSIZE)
#define LOGSYNC_BARRIER(logsize) ((logsize)/4)
/*
#define LOGSYNC_DELTA(logsize) min((logsize)/4, 256*LOGPSIZE)
#define LOGSYNC_BARRIER(logsize) ((logsize)/2)
*/
/*
* log buffer cache synchronization
*/
static DEFINE_SPINLOCK(jfsLCacheLock);
#define LCACHE_LOCK(flags) spin_lock_irqsave(&jfsLCacheLock, flags)
#define LCACHE_UNLOCK(flags) spin_unlock_irqrestore(&jfsLCacheLock, flags)
/*
* See __SLEEP_COND in jfs_locks.h
*/
#define LCACHE_SLEEP_COND(wq, cond, flags) \
do { \
if (cond) \
break; \
__SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
} while (0)
#define LCACHE_WAKEUP(event) wake_up(event)
/*
* lbuf buffer cache (lCache) control
*/
/* log buffer manager pageout control (cumulative, inclusive) */
#define lbmREAD 0x0001
#define lbmWRITE 0x0002 /* enqueue at tail of write queue;
* init pageout if at head of queue;
*/
#define lbmRELEASE 0x0004 /* remove from write queue
* at completion of pageout;
* do not free/recycle it yet:
* caller will free it;
*/
#define lbmSYNC 0x0008 /* do not return to freelist
* when removed from write queue;
*/
#define lbmFREE 0x0010 /* return to freelist
* at completion of pageout;
* the buffer may be recycled;
*/
#define lbmDONE 0x0020
#define lbmERROR 0x0040
#define lbmGC 0x0080 /* lbmIODone to perform post-GC processing
* of log page
*/
#define lbmDIRECT 0x0100
/*
* Global list of active external journals
*/
static LIST_HEAD(jfs_external_logs);
static struct jfs_log *dummy_log;
static DEFINE_MUTEX(jfs_log_mutex);
/*
* forward references
*/
static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
struct lrd * lrd, struct tlock * tlck);
static int lmNextPage(struct jfs_log * log);
static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
int activate);
static int open_inline_log(struct super_block *sb);
static int open_dummy_log(struct super_block *sb);
static int lbmLogInit(struct jfs_log * log);
static void lbmLogShutdown(struct jfs_log * log);
static struct lbuf *lbmAllocate(struct jfs_log * log, int);
static void lbmFree(struct lbuf * bp);
static void lbmfree(struct lbuf * bp);
static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
static int lbmIOWait(struct lbuf * bp, int flag);
static bio_end_io_t lbmIODone;
static void lbmStartIO(struct lbuf * bp);
static void lmGCwrite(struct jfs_log * log, int cant_block);
static int lmLogSync(struct jfs_log * log, int hard_sync);
/*
* statistics
*/
#ifdef CONFIG_JFS_STATISTICS
static struct lmStat {
uint commit; /* # of commit */
uint pagedone; /* # of page written */
uint submitted; /* # of pages submitted */
uint full_page; /* # of full pages submitted */
uint partial_page; /* # of partial pages submitted */
} lmStat;
#endif
static void write_special_inodes(struct jfs_log *log,
int (*writer)(struct address_space *))
{
struct jfs_sb_info *sbi;
list_for_each_entry(sbi, &log->sb_list, log_list) {
writer(sbi->ipbmap->i_mapping);
writer(sbi->ipimap->i_mapping);
writer(sbi->direct_inode->i_mapping);
}
}
/*
* NAME: lmLog()
*
* FUNCTION: write a log record;
*
* PARAMETER:
*
* RETURN: lsn - offset to the next log record to write (end-of-log);
* -1 - error;
*
* note: todo: log error handler
*/
int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
struct tlock * tlck)
{
int lsn;
int diffp, difft;
struct metapage *mp = NULL;
unsigned long flags;
jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
log, tblk, lrd, tlck);
LOG_LOCK(log);
/* log by (out-of-transaction) JFS ? */
if (tblk == NULL)
goto writeRecord;
/* log from page ? */
if (tlck == NULL ||
tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
goto writeRecord;
/*
* initialize/update page/transaction recovery lsn
*/
lsn = log->lsn;
LOGSYNC_LOCK(log, flags);
/*
* initialize page lsn if first log write of the page
*/
if (mp->lsn == 0) {
mp->log = log;
mp->lsn = lsn;
log->count++;
/* insert page at tail of logsynclist */
list_add_tail(&mp->synclist, &log->synclist);
}
/*
* initialize/update lsn of tblock of the page
*
* transaction inherits oldest lsn of pages associated
* with allocation/deallocation of resources (their
* log records are used to reconstruct allocation map
* at recovery time: inode for inode allocation map,
* B+-tree index of extent descriptors for block
* allocation map);
* allocation map pages inherit transaction lsn at
* commit time to allow forwarding log syncpt past log
* records associated with allocation/deallocation of
* resources only after persistent map of these map pages
* have been updated and propagated to home.
*/
/*
* initialize transaction lsn:
*/
if (tblk->lsn == 0) {
/* inherit lsn of its first page logged */
tblk->lsn = mp->lsn;
log->count++;
/* insert tblock after the page on logsynclist */
list_add(&tblk->synclist, &mp->synclist);
}
/*
* update transaction lsn:
*/
else {
/* inherit oldest/smallest lsn of page */
logdiff(diffp, mp->lsn, log);
logdiff(difft, tblk->lsn, log);
if (diffp < difft) {
/* update tblock lsn with page lsn */
tblk->lsn = mp->lsn;
/* move tblock after page on logsynclist */
list_move(&tblk->synclist, &mp->synclist);
}
}
LOGSYNC_UNLOCK(log, flags);
/*
* write the log record
*/
writeRecord:
lsn = lmWriteRecord(log, tblk, lrd, tlck);
/*
* forward log syncpt if log reached next syncpt trigger
*/
logdiff(diffp, lsn, log);
if (diffp >= log->nextsync)
lsn = lmLogSync(log, 0);
/* update end-of-log lsn */
log->lsn = lsn;
LOG_UNLOCK(log);
/* return end-of-log address */
return lsn;
}
/*
* NAME: lmWriteRecord()
*
* FUNCTION: move the log record to current log page
*
* PARAMETER: cd - commit descriptor
*
* RETURN: end-of-log address
*
* serialization: LOG_LOCK() held on entry/exit
*/
static int
lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
struct tlock * tlck)
{
int lsn = 0; /* end-of-log address */
struct lbuf *bp; /* dst log page buffer */
struct logpage *lp; /* dst log page */
caddr_t dst; /* destination address in log page */
int dstoffset; /* end-of-log offset in log page */
int freespace; /* free space in log page */
caddr_t p; /* src meta-data page */
caddr_t src;
int srclen;
int nbytes; /* number of bytes to move */
int i;
int len;
struct linelock *linelock;
struct lv *lv;
struct lvd *lvd;
int l2linesize;
len = 0;
/* retrieve destination log page to write */
bp = (struct lbuf *) log->bp;
lp = (struct logpage *) bp->l_ldata;
dstoffset = log->eor;
/* any log data to write ? */
if (tlck == NULL)
goto moveLrd;
/*
* move log record data
*/
/* retrieve source meta-data page to log */
if (tlck->flag & tlckPAGELOCK) {
p = (caddr_t) (tlck->mp->data);
linelock = (struct linelock *) & tlck->lock;
}
/* retrieve source in-memory inode to log */
else if (tlck->flag & tlckINODELOCK) {
if (tlck->type & tlckDTREE)
p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
else
p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
linelock = (struct linelock *) & tlck->lock;
}
#ifdef _JFS_WIP
else if (tlck->flag & tlckINLINELOCK) {
inlinelock = (struct inlinelock *) & tlck;
p = (caddr_t) & inlinelock->pxd;
linelock = (struct linelock *) & tlck;
}
#endif /* _JFS_WIP */
else {
jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
return 0; /* Probably should trap */
}
l2linesize = linelock->l2linesize;
moveData:
ASSERT(linelock->index <= linelock->maxcnt);
lv = linelock->lv;
for (i = 0; i < linelock->index; i++, lv++) {
if (lv->length == 0)
continue;
/* is page full ? */
if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
/* page become full: move on to next page */
lmNextPage(log);
bp = log->bp;
lp = (struct logpage *) bp->l_ldata;
dstoffset = LOGPHDRSIZE;
}
/*
* move log vector data
*/
src = (u8 *) p + (lv->offset << l2linesize);
srclen = lv->length << l2linesize;
len += srclen;
while (srclen > 0) {
freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
nbytes = min(freespace, srclen);
dst = (caddr_t) lp + dstoffset;
memcpy(dst, src, nbytes);
dstoffset += nbytes;
/* is page not full ? */
if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
break;
/* page become full: move on to next page */
lmNextPage(log);
bp = (struct lbuf *) log->bp;
lp = (struct logpage *) bp->l_ldata;
dstoffset = LOGPHDRSIZE;
srclen -= nbytes;
src += nbytes;
}
/*
* move log vector descriptor
*/
len += 4;
lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
lvd->offset = cpu_to_le16(lv->offset);
lvd->length = cpu_to_le16(lv->length);
dstoffset += 4;
jfs_info("lmWriteRecord: lv offset:%d length:%d",
lv->offset, lv->length);
}
if ((i = linelock->next)) {
linelock = (struct linelock *) lid_to_tlock(i);
goto moveData;
}
/*
* move log record descriptor
*/
moveLrd:
lrd->length = cpu_to_le16(len);
src = (caddr_t) lrd;
srclen = LOGRDSIZE;
while (srclen > 0) {
freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
nbytes = min(freespace, srclen);
dst = (caddr_t) lp + dstoffset;
memcpy(dst, src, nbytes);
dstoffset += nbytes;
srclen -= nbytes;
/* are there more to move than freespace of page ? */
if (srclen)
goto pageFull;
/*
* end of log record descriptor
*/
/* update last log record eor */
log->eor = dstoffset;
bp->l_eor = dstoffset;
lsn = (log->page << L2LOGPSIZE) + dstoffset;
if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
tblk->clsn = lsn;
jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
bp->l_eor);
INCREMENT(lmStat.commit); /* # of commit */
/*
* enqueue tblock for group commit:
*
* enqueue tblock of non-trivial/synchronous COMMIT
* at tail of group commit queue
* (trivial/asynchronous COMMITs are ignored by
* group commit.)
*/
LOGGC_LOCK(log);
/* init tblock gc state */
tblk->flag = tblkGC_QUEUE;
tblk->bp = log->bp;
tblk->pn = log->page;
tblk->eor = log->eor;
/* enqueue transaction to commit queue */
list_add_tail(&tblk->cqueue, &log->cqueue);
LOGGC_UNLOCK(log);
}
jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
/* page not full ? */
if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
return lsn;
pageFull:
/* page become full: move on to next page */
lmNextPage(log);
bp = (struct lbuf *) log->bp;
lp = (struct logpage *) bp->l_ldata;
dstoffset = LOGPHDRSIZE;
src += nbytes;
}
return lsn;
}
/*
* NAME: lmNextPage()
*
* FUNCTION: write current page and allocate next page.
*
* PARAMETER: log
*
* RETURN: 0
*
* serialization: LOG_LOCK() held on entry/exit
*/
static int lmNextPage(struct jfs_log * log)
{
struct logpage *lp;
int lspn; /* log sequence page number */
int pn; /* current page number */
struct lbuf *bp;
struct lbuf *nextbp;
struct tblock *tblk;
/* get current log page number and log sequence page number */
pn = log->page;
bp = log->bp;
lp = (struct logpage *) bp->l_ldata;
lspn = le32_to_cpu(lp->h.page);
LOGGC_LOCK(log);
/*
* write or queue the full page at the tail of write queue
*/
/* get the tail tblk on commit queue */
if (list_empty(&log->cqueue))
tblk = NULL;
else
tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
/* every tblk who has COMMIT record on the current page,
* and has not been committed, must be on commit queue
* since tblk is queued at commit queueu at the time
* of writing its COMMIT record on the page before
* page becomes full (even though the tblk thread
* who wrote COMMIT record may have been suspended
* currently);
*/
/* is page bound with outstanding tail tblk ? */
if (tblk && tblk->pn == pn) {
/* mark tblk for end-of-page */
tblk->flag |= tblkGC_EOP;
if (log->cflag & logGC_PAGEOUT) {
/* if page is not already on write queue,
* just enqueue (no lbmWRITE to prevent redrive)
* buffer to wqueue to ensure correct serial order
* of the pages since log pages will be added
* continuously
*/
if (bp->l_wqnext == NULL)
lbmWrite(log, bp, 0, 0);
} else {
/*
* No current GC leader, initiate group commit
*/
log->cflag |= logGC_PAGEOUT;
lmGCwrite(log, 0);
}
}
/* page is not bound with outstanding tblk:
* init write or mark it to be redriven (lbmWRITE)
*/
else {
/* finalize the page */
bp->l_ceor = bp->l_eor;
lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
}
LOGGC_UNLOCK(log);
/*
* allocate/initialize next page
*/
/* if log wraps, the first data page of log is 2
* (0 never used, 1 is superblock).
*/
log->page = (pn == log->size - 1) ? 2 : pn + 1;
log->eor = LOGPHDRSIZE; /* ? valid page empty/full at logRedo() */
/* allocate/initialize next log page buffer */
nextbp = lbmAllocate(log, log->page);
nextbp->l_eor = log->eor;
log->bp = nextbp;
/* initialize next log page */
lp = (struct logpage *) nextbp->l_ldata;
lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
return 0;
}
/*
* NAME: lmGroupCommit()
*
* FUNCTION: group commit
* initiate pageout of the pages with COMMIT in the order of
* page number - redrive pageout of the page at the head of
* pageout queue until full page has been written.
*
* RETURN:
*
* NOTE:
* LOGGC_LOCK serializes log group commit queue, and
* transaction blocks on the commit queue.
* N.B. LOG_LOCK is NOT held during lmGroupCommit().
*/
int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
{
int rc = 0;
LOGGC_LOCK(log);
/* group committed already ? */
if (tblk->flag & tblkGC_COMMITTED) {
if (tblk->flag & tblkGC_ERROR)
rc = -EIO;
LOGGC_UNLOCK(log);
return rc;
}
jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
if (tblk->xflag & COMMIT_LAZY)
tblk->flag |= tblkGC_LAZY;
if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
(!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
|| jfs_tlocks_low)) {
/*
* No pageout in progress
*
* start group commit as its group leader.
*/
log->cflag |= logGC_PAGEOUT;
lmGCwrite(log, 0);
}
if (tblk->xflag & COMMIT_LAZY) {
/*
* Lazy transactions can leave now
*/
LOGGC_UNLOCK(log);
return 0;
}
/* lmGCwrite gives up LOGGC_LOCK, check again */
if (tblk->flag & tblkGC_COMMITTED) {
if (tblk->flag & tblkGC_ERROR)
rc = -EIO;
LOGGC_UNLOCK(log);
return rc;
}
/* upcount transaction waiting for completion
*/
log->gcrtc++;
tblk->flag |= tblkGC_READY;
__SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
LOGGC_LOCK(log), LOGGC_UNLOCK(log));
/* removed from commit queue */
if (tblk->flag & tblkGC_ERROR)
rc = -EIO;
LOGGC_UNLOCK(log);
return rc;
}
/*
* NAME: lmGCwrite()
*
* FUNCTION: group commit write
* initiate write of log page, building a group of all transactions
* with commit records on that page.
*
* RETURN: None
*
* NOTE:
* LOGGC_LOCK must be held by caller.
* N.B. LOG_LOCK is NOT held during lmGroupCommit().
*/
static void lmGCwrite(struct jfs_log * log, int cant_write)
{
struct lbuf *bp;
struct logpage *lp;
int gcpn; /* group commit page number */
struct tblock *tblk;
struct tblock *xtblk = NULL;
/*
* build the commit group of a log page
*
* scan commit queue and make a commit group of all
* transactions with COMMIT records on the same log page.
*/
/* get the head tblk on the commit queue */
gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
list_for_each_entry(tblk, &log->cqueue, cqueue) {
if (tblk->pn != gcpn)
break;
xtblk = tblk;
/* state transition: (QUEUE, READY) -> COMMIT */
tblk->flag |= tblkGC_COMMIT;
}
tblk = xtblk; /* last tblk of the page */
/*
* pageout to commit transactions on the log page.
*/
bp = (struct lbuf *) tblk->bp;
lp = (struct logpage *) bp->l_ldata;
/* is page already full ? */
if (tblk->flag & tblkGC_EOP) {
/* mark page to free at end of group commit of the page */
tblk->flag &= ~tblkGC_EOP;
tblk->flag |= tblkGC_FREE;
bp->l_ceor = bp->l_eor;
lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
cant_write);
INCREMENT(lmStat.full_page);
}
/* page is not yet full */
else {
bp->l_ceor = tblk->eor; /* ? bp->l_ceor = bp->l_eor; */
lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
INCREMENT(lmStat.partial_page);
}
}
/*
* NAME: lmPostGC()
*
* FUNCTION: group commit post-processing
* Processes transactions after their commit records have been written
* to disk, redriving log I/O if necessary.
*
* RETURN: None
*
* NOTE:
* This routine is called a interrupt time by lbmIODone
*/
static void lmPostGC(struct lbuf * bp)
{
unsigned long flags;
struct jfs_log *log = bp->l_log;
struct logpage *lp;
struct tblock *tblk, *temp;
//LOGGC_LOCK(log);
spin_lock_irqsave(&log->gclock, flags);
/*
* current pageout of group commit completed.
*
* remove/wakeup transactions from commit queue who were
* group committed with the current log page
*/
list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
if (!(tblk->flag & tblkGC_COMMIT))
break;
/* if transaction was marked GC_COMMIT then
* it has been shipped in the current pageout
* and made it to disk - it is committed.
*/
if (bp->l_flag & lbmERROR)
tblk->flag |= tblkGC_ERROR;
/* remove it from the commit queue */
list_del(&tblk->cqueue);
tblk->flag &= ~tblkGC_QUEUE;
if (tblk == log->flush_tblk) {
/* we can stop flushing the log now */
clear_bit(log_FLUSH, &log->flag);
log->flush_tblk = NULL;
}
jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
tblk->flag);
if (!(tblk->xflag & COMMIT_FORCE))
/*
* Hand tblk over to lazy commit thread
*/
txLazyUnlock(tblk);
else {
/* state transition: COMMIT -> COMMITTED */
tblk->flag |= tblkGC_COMMITTED;
if (tblk->flag & tblkGC_READY)
log->gcrtc--;
LOGGC_WAKEUP(tblk);
}
/* was page full before pageout ?
* (and this is the last tblk bound with the page)
*/
if (tblk->flag & tblkGC_FREE)
lbmFree(bp);
/* did page become full after pageout ?
* (and this is the last tblk bound with the page)
*/
else if (tblk->flag & tblkGC_EOP) {
/* finalize the page */
lp = (struct logpage *) bp->l_ldata;
bp->l_ceor = bp->l_eor;
lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
jfs_info("lmPostGC: calling lbmWrite");
lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
1);
}
}
/* are there any transactions who have entered lnGroupCommit()
* (whose COMMITs are after that of the last log page written.
* They are waiting for new group commit (above at (SLEEP 1))
* or lazy transactions are on a full (queued) log page,
* select the latest ready transaction as new group leader and
* wake her up to lead her group.
*/
if ((!list_empty(&log->cqueue)) &&
((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
/*
* Call lmGCwrite with new group leader
*/
lmGCwrite(log, 1);
/* no transaction are ready yet (transactions are only just
* queued (GC_QUEUE) and not entered for group commit yet).
* the first transaction entering group commit
* will elect herself as new group leader.
*/
else
log->cflag &= ~logGC_PAGEOUT;
//LOGGC_UNLOCK(log);
spin_unlock_irqrestore(&log->gclock, flags);
return;
}
/*
* NAME: lmLogSync()
*
* FUNCTION: write log SYNCPT record for specified log
* if new sync address is available
* (normally the case if sync() is executed by back-ground
* process).
* calculate new value of i_nextsync which determines when
* this code is called again.
*
* PARAMETERS: log - log structure
* hard_sync - 1 to force all metadata to be written
*
* RETURN: 0
*
* serialization: LOG_LOCK() held on entry/exit
*/
static int lmLogSync(struct jfs_log * log, int hard_sync)
{
int logsize;
int written; /* written since last syncpt */
int free; /* free space left available */
int delta; /* additional delta to write normally */
int more; /* additional write granted */
struct lrd lrd;
int lsn;
struct logsyncblk *lp;
unsigned long flags;
/* push dirty metapages out to disk */
if (hard_sync)
write_special_inodes(log, filemap_fdatawrite);
else
write_special_inodes(log, filemap_flush);
/*
* forward syncpt
*/
/* if last sync is same as last syncpt,
* invoke sync point forward processing to update sync.
*/
if (log->sync == log->syncpt) {
LOGSYNC_LOCK(log, flags);
if (list_empty(&log->synclist))
log->sync = log->lsn;
else {
lp = list_entry(log->synclist.next,
struct logsyncblk, synclist);
log->sync = lp->lsn;
}
LOGSYNC_UNLOCK(log, flags);
}
/* if sync is different from last syncpt,
* write a SYNCPT record with syncpt = sync.
* reset syncpt = sync
*/
if (log->sync != log->syncpt) {
lrd.logtid = 0;
lrd.backchain = 0;
lrd.type = cpu_to_le16(LOG_SYNCPT);
lrd.length = 0;
lrd.log.syncpt.sync = cpu_to_le32(log->sync);
lsn = lmWriteRecord(log, NULL, &lrd, NULL);
log->syncpt = log->sync;
} else
lsn = log->lsn;
/*
* setup next syncpt trigger (SWAG)
*/
logsize = log->logsize;
logdiff(written, lsn, log);
free = logsize - written;
delta = LOGSYNC_DELTA(logsize);
more = min(free / 2, delta);
if (more < 2 * LOGPSIZE) {
jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
/*
* log wrapping
*
* option 1 - panic ? No.!
* option 2 - shutdown file systems
* associated with log ?
* option 3 - extend log ?